KR101667091B1 - Textured alumina layer - Google Patents

Abstract

The present invention relates to a cutting tool insert machined by chip removal comprising a body of a hard alloy of cemented carbide, cermet, ceramic or cubic boron nitride based material, wherein the hard, abrasion resistant coating CVD < / RTI > The coating is {01-15} and / comprises at least one of α-Al ₂ O ₃ layer having a thickness of 0.5㎛ ~ 40㎛, and the α-Al ₂ O ₃ layer has excellent wear resistance and showing a metal cutting performance Or {10-15} texture.

Description

Textured Alumina Layer {TEXTURED ALUMINA LAYER}

The invention the textured alpha-alumina (α-Al ₂ O ₃₎ relates to a cutting tool coating comprising a body coated with a layer, and also relates to a method and its use for producing such a coated cutting tool. This layer is grown by chemical vapor deposition (CVD), and the present invention provides an oxide layer with excellent abrasion and good performance in chip forming machining.

Typically, a CVD alumina-based coating consists of an inner layer of carbonitride titanium and an outer layer of alpha -Al ₂ O ₃ . About 15 years ago, it was discovered that further improvement of the alumina layer was possible by controlling the crystallographic orientation of the layer (texture). This has been made possible by the development of new synthesis routes involving nucleation and growth sequences, layer bonding, sequencing of reactant gases and addition of texturing modifiers and / or utilization of alumina conversion layers. In general, textures are evaluated using the concepts of X-ray diffraction (XRD) techniques and texture coefficients.

Various combinations / Nucleation  Floor and Growth Sequence  Synthesis of Textured Alumina Layer to Use

US 7094447 describes a process for making a textured? -Al ₂ O ₃ layer having improved abrasion resistance and toughness. The? -Al ₂ O ₃ layer is formed on the (Ti, Al) (C, O, N) bonding layer using a nucleation sequence composed of aluminizing and oxidation steps. This layer is characterized by a strong {012} growth texture as determined by XRD.

US 7442431 discloses the use of textured alpha-Al ₂ (Al, Ti) on a (Ti, Al) (C, O, N) bond layer using a nucleation sequence consisting of short pulses and purging Ti- O ₃ layer is described. This layer is characterized by a strong {110} growth texture as determined by XRD.

US 7455900 discloses a method of forming a textured α-Al ₂ O ₃ (Ti, Al) (C, O, N) bond layer using a nucleation sequence consisting of a short pulse and a purging consisting of Ti + Layer is prepared. This layer is characterized by a strong {116} growth texture as determined by XRD.

US 7442432 discloses and describes a method of manufacturing techniques and similar, a modified technique (Ti, Al) (C, O, N) a textured α-Al ₂ O in the bonding layer ₃ layer as described in No. US 7455900. This layer is characterized by a strong {104} growth texture as determined by XRD.

US 2007104945 discloses that nucleation controlled α-Al ₂ O ₃ The base material of the textured α-Al ₂ O ₃ coated cutting tool insert with a layer texture is obtained. This layer is characterized by a strong growth texture as determined by XRD.

US 2008187774 discloses a texture having {006} texture grown, as determined by XRD - the α-Al ₂ O ₃ curing Coated cutting tool inserts are described.

US 6333103 discloses a {1010} growth of a grown on TiCO bonding layer characterized by the texture textured α-Al ₂ O _3, as determined by XRD Describe the layer.

Synthesis of Textured Alumina Layer Using Sequencing of Reaction Gases

US 5654035 describes a body coated with a refractory monolayer or multilayer, wherein a specific layer is formed by controlled microstructure and phase composition with a crystal plane grown in a preferential direction with respect to the surface of the coated body (growth texture) . The textured? -Al ₂ O ₃ layer is obtained by sequencing the reaction gas in the order of CO ₂ , CO and AlCl ₃ . This layer is characterized by a strong {012} growth texture as determined by XRD.

US 5766782 describes a refractory single layer or multi-layer coated cutting tool comprising? -Al ₂ O ₃ , wherein a specific layer is characterized by a controlled growth texture on the surface of the coated body. First, a textured α-Al ₂ O ₃ layer is obtained by sequencing the reaction gas such that CO ₂ and CO are supplied to the reactor in an N ₂ and / or Ar atmosphere and then H ₂ and AlCl ₃ are supplied to the reactor . This layer is characterized by a {104} growth texture as determined by XRD.

texture Converting agent  Used Textured  Synthesis of alumina layer

US 7011867 discloses as will be described a cutting tool coating comprising one or more refractory compound layers, and the outside of at least one of α-Al ₂ O ₃ layer, and the α-Al ₂ O ₃ layer is determined by XRD strong {300} growth texture and columnar crystal structure. The microstructure and texture are obtained by adding ZrCl ₄ as a texture conversion agent to the reaction gas at the time of growth.

US 5980988 discloses a base material and a {110} a textured α-Al ₂ O ₃ layer, as obtained by using SF ₆ as a texture transform at the time of the growth. This texture is determined by XRD.

US 5702808 describes a {110} textured? -Al ₂ O ₃ layer as obtained by sequencing SF ₆ and H ₂ S during growth. This texture is determined by XRD.

The conversion layer  Used Textured  Synthesis of alumina layer

No. 4,111,111 discloses a method of producing a laminate comprising an alumina core layer having a thickness of 20 to 200 nm, The {001} textured α-Al ₂ O ₃ layer is described. This texture is determined by electron backscattering diffraction (EBSD).

The EBSD description and, pole figures, polar plots (pole plots), orientation distribution functions (ODFs) and usage analysis for texture evaluation by the texture index, for example of the texture analysis Introduction: macro texture, micro-text up, and direction mapping (mapping), Valerie Randle and Olaf Engler, (ISBN 90-5699-224-4) pp . 13-40.

Typically, the evaluation of the texture may include:

1) composition of ODF,

2) identification of the Euler angles? ₁ ,? And? ₂ (see FIG. 1) and their corresponding ODF density and texture index of the component,

3) composition of the poles (s) of the associated texture components, and

4) Construction of the extreme plot (s) of the associated texture component.

It is an object of the present invention to provide CVD controlled, textured α-Al ₂ O ₃ , which has good abrasion and chip- Layer.

It is also an object of the present invention to provide such a-Al ₂ O ₃ Layer on a substrate.

Surprisingly, even with the growth conditions alone, the specific? -Al ₂ O ₃ Control of the layer texture was obtained, and as a result this layer was found to have improved metal cutting performance.

Figure 1 defines the Euler angles φ ₁ , φ and φ ₂ used in the ODF representation for the crystallographic directions.
2 is, a) {01-15} a textured α-Al ₂ O ₃ according to the invention Layer (II) and Ti (C, N) layer (I), and b) a {001} textured α-Al ₂ O ₃ Scattered SEM micrographs of ion-polished cross-sections of layer (II) and Ti (C, N) layer (I).
Figure 3 shows a) textured α-Al ₂ O _{3 with} {01-15} and {10-15} solutions according to the invention, respectively, denoted A and A ' Layer, and a, b) {0001} The textured α-Al ₂ O ₃ according to the prior art; (ODF Euler angle and density) of the layer.
Figure 4 is a) {01-15} texture component, b) {10-15} texture component according to the invention, and c) {0001} The textured α-Al ₂ according to the prior art according to the invention O ₃ Layer EBSD pole figure.
Figure 5 is a) {01-15} texture component, b) {10-15} texture component according to the invention, and c) {0001} The textured α-Al ₂ according to the prior art according to the invention O ₃ Layer plot of EBSD. is the angle from the center (x = 0) to the edge (x = 90) of the pole figure (see Fig. 4). MUD is a multi-unit distribution.

According to the present invention there is provided a cutting tool insert for chip removing machining comprising a body of hard alloy of cemented carbide, cermet, ceramic, cubic boron nitride based material on which a hard, And this coating is applied in a {01-15} and / or {10-15} texture (crystallographic direction), preferably in rotational symmetry (fiber texture), with respect to the surface normal of the coated body And at least one? -Al ₂ O ₃ layer configured.

The texture has a ODF texture index greater than 1, preferably 1 < texture index < 50, most preferably 2 < texture index < 10, and {01-15} and {10 -15} represents a texture component that satisfies the solution.

? ₁ ? 90 °, 17 ° <? <47 °, preferably 22 °, having an ODF density of <100, preferably 10 <ODF density <50, ? &Lt; 42 °, and 1 ° &lt;? ₂ <59 °, preferably 10 ° <? ₂ <50 °, and / or

Ii) 0 °??? ₁ ? 90 °, 17 ° <? <47 °, preferably 22 °, having an ODF density of <100, preferably 10 <ODF density < ? <42 °, and 61 ° <φ ₂ <119 °, preferably 70 ° <φ ₂ <110 °.

The ODFs were ion-polished over the display area using series expansion with L _max = 34 with a resolution of 32 x 32 x 32 points, a Gaussian half width of 5 °, and a clustering of 5 °. The alpha -Al ₂ O ₃ upper surface layer Lt; RTI ID = 0.0 &gt; EBSD &lt; / RTI &gt;

The? -Al ₂ O ₃ layer has a columnar crystal structure with a thickness of 0.5 μm to 40 μm, preferably 0.5 μm to 20 μm, and most preferably 1 μm to 10 μm, and all the columns have a layer thickness Has essentially the same column width of 0.2 탆 to 5 탆, preferably 0.2 탆 to 2.5 탆, and most preferably 0.2 탆 to 1.5 탆 across the layer thickness when measured adjacent to the center of the substrate.

The coating can be applied to the entire coating thickness, e.g., TiN, TiC or Ti (C, O, N) or other coating thicknesses of from 0.5 to 40 m, preferably from 0.5 to 20 m and most preferably from 1 to 10 m, Ti, TiC, Ti (C, O, N) or other Al ₂ O ₃ isomers, preferably Al ₂ O ₃ isotopes, preferably Ti Preferably an outer single layer of TiN and / or Ti (C, O, N) and / or a multilayer coating.

Optionally, the coated body is post-treated, such as by wet blasting, brushing, etc., so as to obtain the desired surface quality and / or edge shape.

The deposition method for the? -Al ₂ O ₃ layer of the present invention can be carried out in a mixed gas of H ₂ , CO ₂ , CO, H ₂ S, HCl and AlCl ₃ at a gas pressure of 50 to 150 mbar, Based on chemical vapor deposition at temperatures of 950 ° C to 1050 ° C. According to the present invention, the CO ₂ / CO gas flow rate is 0.3? (CO ₂ / CO) | at a cycle of 1 minute to 60 minutes, preferably 2 minutes to 30 minutes. _low ? 1.2, preferably 0.5? (CO ₂ / CO) | Lower gas flow rates of _low ≤ 1.0 and 1.8 ≤ (CO ₂ / CO) | _high ? 3.0, preferably 1.8? (CO ₂ / CO) | between higher gas flow rates of _high &lt; = 2.5, upwardly and downwardly, continuously or stepwise. It is within the purview of those skilled in the art to determine the gas flow and gas mixture in accordance with the present invention.

The present invention also relates to a cutting tool having a cutting rate of 75 to 600 m / min, preferably 150 to 600 m / min, according to the cutting speed and insert shape, in the case of milling, 0.08 to 0.8 mm, preferably 0.1 to 0.6 mm To the use of a cutting tool insert according to the above for chip removal machining with an average feed per tool edge.

Example  One

Initially, a cemented carbide cutting insert having a composition of 5.5 wt% Co, 8 wt% cubic carbide, and balance WC was coated with a 6 탆 thick MTCVD Ti (C, N) layer. Between cycles during the coating at a subsequent stage of manufacture and the cutting insert, the 5㎛ thick α-Al ₂ O ₃ layer is a 20-minute process conditions 1 and 2 (see Table 1) at a cycle of, upward and downward, CO ₂ / The gas flow rate of the CO was continuously deposited and ramping.

Example  2

Example 1 was repeated with a constant CO ₂ / CO gas flow rate of 2.0.

Example  3

The layers from Examples 1 and 2 were characterized by SEM and EBSD using a LEO Ultra 55 Scanning Electron Microscope equipped with HKL Nordlys II EBSD detector and operated at 15 kV. The normal channel 5 software version 5.0.9.0 was used for data collection. This channel 5 software was used for data analysis of texture exponents, poles and extreme plots as well as calculations of ODFs, Euler angles and densities. Samples for EBSD were obtained by ion polishing the upper surface of the alpha -Al ₂ O ₃ layer using a JEOL SM-09010 cross-sectional polisher system.

2 is, a) Example 1 (invention) and b) Example 2 (Reference) a Ⅱ backscattered SEM micrograph of α-Al ₂ O ₃ layer ion-polished cross section of the labeled within the image for the city do. Both layers represent a columnar crystal structure. The layers of the present invention exhibit column widths in the range of 0.2 mu m to 1.7 mu m narrower than the column widths of the reference layer.

Figure 3 shows a) a-Al ₂ O ₃ layer textured from Example 1 with {01-15} and {10-15} solutions marked with A and A ', respectively, with texture index of 6.3 and b (ODF Euler Angle and Density) as deduced from the EBSD data of the {0001} textured a-Al ₂ O ₃ layer of Example 2 with a texture index of 5.5. Euler angles φ ₁ , φ and φ ₂ for the {01 - 15} texture components are centered at φ ₂ of about 30 ° at φ of about 30 ° at about 0 ° ≤φ ₁ ≤ 90 ° Euler angles φ ₁ , φ and φ ₂ for the {10 - 15} texture components at about 0 ° ≤φ ₁ ≤ 90 ° at Φ of about 30 °, at φ ₂ of about 90 ° Centered. From the channel 5 software, an ODF density value of 23 for {01-15} was obtained. These results illustrate the {10 - 15} fiber textured layer in Example 1.

In addition, the pole geometry and pole slots of the fiber texture have been constructed.

Figure 4 shows the pole figure of a) {01-15} and b) {10-15} texture components of the layer from Example 1. 4 (c) shows the pole figure of the second embodiment.

Figure 5 shows the extreme plots of a) {01-15} and b) {10-15} texture components of the layer from Example 1. FIG. 5C shows the extreme plot of the second embodiment. ? is the angle from the center (? = 0) to the edge (? = 90) of the pole figure in FIG. MUD is a multi-unit distribution.

Example  4

Coated inserts from Example 1 and Example 2 with comparative grades were tested in continuous turning applications at the following cutting conditions.

Workpiece: Cylindrical bar

Material: Ck45

Insert Type: CNMG120408

Cutting speed: 400 m / min

Feed: 0.45 mm / rev

Cutting depth: 2.0 mm

Remark: Cooling water

Measurements of edge wear, Vb (mm), after 12 minutes at the cuts are shown in Table 2.

Claims (13)

A cutting tool insert for machining by chip removal,
The cutting tool insert comprising at least one of α-Al ₂ O ₃ layer having a thickness of 0.5㎛ on said body, comprising a body of cemented carbide, cermet, ceramics or cubic boron nitride-based light alloy material ~ 40㎛ A hard abrasion resistant coating is deposited by CVD,
The α-Al ₂ O ₃ layer is {01-15} and / or a cutting tool insert, it characterized in that the textured as {10-15}. The method according to claim 1,
Characterized in that the texture is textured. The method according to claim 1,
Characterized in that the texture has an ODF texture index of more than one. 3. The method of claim 2,
1 < texture index < 50. The method according to claim 1,
The texture represents a texture component with an ODF representation with 1 < ODF density < 100, with the following Euler angles,
_{Ⅰ) 0 ° ≤ φ 1 ≤} 90 °, 17 ° <Φ <47 °, and 1 ° <φ ₂ <59 ° and
Ii) one or both of the {01-15} and {10-15} solutions with 0 ° ≤ φ ₁ ≤ 90 °, 17 ° <Φ <47 ° and 61 ° <φ ₂ <119 ° Of the cutting tool insert. 6. The method of claim 5,
I) 0??? ₁ ? 90, 22 <? <42, and 10 <? ₂ <50 and
Ii) 0 ° ≤ φ ₁ ≤ 90 °, 22 ° <Φ <42 °, and 70 ° <φ ₂ <110 °. 6. The method of claim 5,
10 < ODF density < 50. The method according to claim 1,
Characterized in that the? -Al ₂ O ₃ layer has a columnar crystal structure and all the pillars essentially have the same column width of 0.2 μm to 5 μm over the thickness of the α-Al ₂ O ₃ layer Tool insert. 9. The method of claim 8,
The pole width, cutting tool insert, characterized in that 0.2㎛ ~ 2.5㎛ throughout the α-Al ₂ O ₃ layer. The method according to claim 1,
To a total thickness of 0.5 to 40 탆, said coating comprising at least one of an inner coating and an outer coating,
Each of the inner coating and the outer coating is a TiN, TiC, Ti (C, O, N) or different Al ₂ O or a single layer coating of the _three allotropes, TiN, TiC, Ti (C , O, N) or different Al ₂ O Wherein the multilayer coating is a multi-layer coating of one or more of the following _three kinds of isotropes. At least one? -Al ₂ O ₃ layer is formed by chemical vapor deposition at a temperature of 950 ° C. to 1050 ° C. in mixed H ₂ , CO ₂ , CO, H ₂ S, HCl and AlCl ₃ at a gas pressure of 50 to 150 mbar A method of making a cutting tool insert comprising a body of a cemented carbide, cermet, ceramic or cubic boron based material deposited with a hard abrasion resistant coating,
The CO ₂ / CO gas flow rate is 0.3? (CO ₂ / CO) | at a cycle of 1 minute to 60 minutes. lower gas flow rate of _low ? 1.2 and 1.8? (CO ₂ / CO) | characterized in that it is periodically changed between upward and downward, continuously or stepwise, between higher gas flow rates of _high ? 3.0. 12. The method of claim 11,
The lower gas flow rate is 0.5? (CO ₂ / CO) | _low ≤ 1.0 and the higher gas flow rate is 1.8 ≤ (CO ₂ / CO) | _high &lt; / = 2.5. &lt; / RTI &gt; 11. The method according to any one of claims 1 to 10,
The cutting tool insert is characterized in that it is used for chip removal machining, with an average feed per cutting edge of 0.08 to 0.8 mm in the case of milling, at a cutting speed of 75 to 600 m / min, depending on the cutting speed and insert shape A cutting tool insert.

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